GUANTANAMO BAY NAVAL BASE, Cuba (AP) — Attorney James Connell has visited his client inside the secret Guantanamo prison complex known as Camp 7 only once, taken in a van with covered windows on a circuitous trek to disguise the route on the scrub brush-and-cactus covered military base.

Connell is allowed to say virtually nothing about what he saw in the secret camp where the most notorious terror suspects in U.S. custody are held except that it is unlike any detention facility he's encountered.

"It's much more isolating than any other facility that I have known," the lawyer says. "I've done cases from the Virginia death row and Texas death row and these pretrial conditions are much more isolating."

The Camp 7 prison unit is so shrouded in secrecy that its location on the U.S. base in Cuba is classified and officials refuse to discuss it. Now, two separate but related events are forcing it into the limelight.

In Washington, the Senate Intelligence Committee voted on April 3 to declassify a portion of a review of the U.S. detention and interrogation program in the aftermath of the Sept. 11, 2001, al-Qaida attack. The report, the release of which is opposed by the CIA, is expected to be sharply critical of the treatment of prisoners, including some now held in Camp 7.

And on Monday, a judge in Guantanamo will open a hearing into the sanity of one of those prisoners, Ramzi Binalshibh, whose courtroom outbursts about alleged mistreatment in Camp 7 have halted the already bogged-down effort to try five men in the Sept. 11 attacks, all of whom are held there.

Both issues are deeply intertwined. Binalshibh has accused the government of making noises and vibrations inside Camp 7 to deliberately keep him awake, reminiscent of the intentional sleep deprivation, along with other forms of abuse, that his lawyers say he endured at the hands of the CIA from the time he was captured in Pakistan in September 2002 to when he was brought to Guantanamo four years later.

Military officials deny doing anything intentional to disrupt his sleep. Prosecutors say his accusations are delusions, though they still believe he is mentally competent to stand trial. His lawyers say he is competent, but are not convinced officials have adequately investigated his complaints.

His mental state is somewhat murky. Court records show Binalshibh has been treated while in Guantanamo with medications that are used for bipolar disorder and schizophrenia, but he did not participate in a court-ordered mental evaluation in January.

The judge, Army Col. James Pohl, could decide to sever Binalshibh from the case against his co-defendants, all of whom are being tried by military commission on charges that include terrorism and murder and face the death penalty if convicted.

Another possibility is that his inability to sleep and his fevered outbursts in court, which prompted the judge to order him removed from the courtroom in December, are a result of post-traumatic stress from his treatment at secret CIA interrogation centers known as black sites, said Anne Fitzgerald, director of the research and crisis response program for Amnesty International.

"The problem is that because everything is done in secret and there is so little opportunity for even the lawyers to have access to their clients it's difficult for anybody to figure out what is actually happening," said Fitzgerald, who is at the base to observe the sanity board proceedings.

Camp 7 has never been part of the scripted tours of Guantanamo offered to journalists and there are no published photos. It's not even mentioned on a military media handout about the detention center, which otherwise notes that the military "conducts safe, humane, legal and transparent care and custody of detainees."

Military officials, while insisting that they adhere to international human rights standards, refuse to describe Camp 7. "I'm not even functionally allowed to discuss the place," said Army Lt. Col. Todd Breasseale, a Pentagon spokesman.

A few facts have come out through government reports and court testimony. It apparently holds 15 of the 152 prisoners at Guantanamo. Those held in Camp 7 include Khalid Sheikh Mohammed, who has portrayed himself as the mastermind of the Sept. 11 attack and is on trial with Binalshibh. Also held there is a Saudi prisoner charged with orchestrating the deadly bombing of the USS Cole in 2000.

The men are apparently held in solid-walled cells — as opposed to the cage-like structures used soon after the U.S. began using Guantanamo as a prison in 2002 — that are intended to limit their ability to communicate with each other, and they are allowed up to four hours per day of exercise, according to a Government Accountability Office report.

The secret camp also is apparently falling apart.

Marine Gen. John F. Kelly, commander of Miami-based Southern Command, told Congress that Camp 7 has become "increasingly unsustainable due to drainage and foundation issues" and needs to be replaced. But officials balked at the proposed $49 million price tag and the military scrapped the idea for a replacement and is making repairs out of existing funds, said Army Col. Greg Julian, a spokesman for Southern Command, which oversees Guantanamo.

James Harrington, a lawyer for Binalshibh, said he does not believe problems with the foundation — which Julian described as "heaving and shifting" — are responsible for the vibrations and sounds that his client says keep him awake.

The judge granted all five defense teams a request to visit Camp 7 one time for up to 12 hours to inspect conditions. Because of an ongoing dispute over the rules for handling classified evidence however, only Connell, who represents defendant Ammar al-Baluchi, has been inside. He went in August, riding in the van with windows covered in heavy-duty paper and a makeshift interior barrier so he could not see the driver.

It is not clear whether one visit closely monitored by prison authorities would reveal the cause of Binalshibh's distress. His previous military lawyers, Navy Cmdr. Suzanne Lachelier and Lt. Richard Federico, were allowed inside Camp 7 in November 2008 for about two hours. With Connell, they are the only other defense lawyers known to have ever been inside the facility. They could not determine a cause for his complaints.

The secrecy and security, Lachelier recalls, seemed excessive then and she remains skeptical. "There's no way to explain the security measures that they use from the perspective of the safety of the guards or the safety of the detainees, beyond that they must be hiding something."

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